The Glutamate Synapse in the Developing Hippocampus

Principal Investigator: Bengt Gustafsson

The glutamate synapse is the predominant excitatory synapse in the brain and malfunction of these synapses results in a number of neurological diseases. Using the in vitro hippocampal slice preparation and electrophysiological technique (field and whole-cell recording) we investigate the physiology of the glutamate synapse focusing on its plastic properties in the developing brain. During brain development there is an enormous generation of glutamate synapses and activity-dependent synaptic plasticity is instrumental in forming the precise mature pattern of synaptic connectivity. An appropriate wiring of developing neuronal networks is thus essential for adult brain functions, and knowledge of the principles for this wiring seems therefore essential.

In our present work we examine the idea that the glutamate synapse in the developing brain has a unique set-up of activity-driven plasticities to allow for a dynamic organization/reorganization of synaptic connections throughout development. In this work we use both the “model” glutamate synapse, the CA3 - CA1 pyramidal cell connection, as well as the much less studied perforant path – CA1 connection, in order to examine whether glutamate synapses belonging to the two functionally different cortical inputs to the hippocampal CA1 region, the direct and indirect (trisynaptic) path, respectively, differ in their plastic properties and developmental profile.